Two-sided cooking apparatus or clamshell cooking systems are capable of simultaneously cooking two sides of various food products, such as, hamburger patties, sausage patties, chicken, or other foodstuffs. Clamshell cooking systems are often utilized in the fast-food industry because they reduce the overall cooking time associated with the foodstuffs, such as, frozen hamburger patties, and the amount of operator attention required for cooking the foodstuffs.
The clamshell cooking system generally includes an upper cooking plate or platen and a lower cooking plate or platen. The upper cooking platen is coupled to a platen support arm for swinging movement between a lower cooking position overlying lower cooking platen and a raised position inclined upwardly from the lower cooking platen. The upper cooking platen can be manually or automatically moved between the lower cooking position and the raised position.
When the upper cooking platen is in the lower cooking position, it overlies the lower cooking platen and is separated from the lower cooking platen by a gap. The gap is generally set to a distance associated with the thickness of the foodstuff which is being cooked. For example, hamburger patties are preformed in several different nominal sizes (a quarter pound patty has a larger thickness than a regular patty). The gap can be manually, pneumatically, or electronically adjusted so the foodstuff is appropriately cooked between the upper cooking platen and the lower cooking platen. In such systems, an operator selects the gap size and inherently selects a cooking time via an operator interface for the food item being cooked. The gap size may be selected by a numeric value or by an identification of the food item being cooked.
Conventional two-sided cooking systems can be susceptible to waste and improperly cooked food if the operator does not select the correct gap size (and, hence, the proper cooking time). Conventional systems can have a menu of twenty or more possible selections when breakfast, lunch, and dinner selections are included. If the operator selects the wrong item, the food item is not cooked properly. For example, if the operator is cooking four 1.6 ounce hamburger patties and improperly selects a gap size for 1.6 ounce hamburger patties, the hamburger patties are overcooked and must be thrown away. Thus, conventional systems are susceptible to operator selection errors.
In addition, conventional two-sided cooking systems are not able to adjust to variations in thickness of the foodstuff because there is only one selection per food item. For example, four-ounce hamburger patties can vary in thickness from +/-0.15 inches. The variation between patties is generally consistent per batch (e.g., the thickness does not vary greatly between patties within a box). However, from one box to another box or from one case to another case, the food item thickness can vary greatly (4 oz patties can very over 0.030 inches). Thus, conventional systems cannot optimize cooking operations for variations in foodstuff sizes.
Additionally, the gap must be adjusted during the cooking operation to accommodate the decrease in size of the hamburger patty as it is cooked. Hamburger patties are generally frozen for storage and transportation. The frozen patties are relatively rigid when initially placed on the lower cooking platen, and, if the upper cooking platen rests only on the thickest patty or patties, even small differences in the thickness of the patties in the group being cooked could delay good heat-transmitting contact between the upper platen and some of the thinner patties. Poor heat transmission results in uneven cooking of the patties. Further, the patties often soften and shrink or decrease in thickness as they thaw and cook. The gap must accommodate this change in thickness during the cooking operation. Further still, the gap must be set so that the hamburger patty is protected from the weight of the upper cooking platen. If the weight of the upper cooking platen is unrestrained or uncontrolled, the upper cooking platen could excessively compress or compact the hamburger patties and adversely affect the texture and appearance of the cooked patties.
Thus, clamshell cooking systems present several special problems related to the adjustment of the gap between the upper and lower cooking platens. These problems include accommodating variations in initial thickness of the individual patties in the group being cooked, accommodating the decrease in thickness of the patties that occurs during cooking, preventing excess compaction of the patties, preventing operator errors in gap thickness and cooking time selections, and accommodating different groups of patties of nominally different thicknesses.
Heretofore, clamshell cooking systems have relied on gravity to force the upper cooking platen onto groups of patties on the lower platen. Platen stops also can be provided to control the minimum spacing (the smallest acceptable spacing or gap) between the upper platen and the lower platen during cooking, thereby preventing excessive compaction of the cooked patties. The platen stops generally had to be manually manipulated to adjust the size of the gap between the upper cooking platen and the lower cooking platen. The use of manually manipulated stop pins is disadvantageous because the stop pins make it difficult to clean the upper platen. Further, stop pins which are near or in the cooking area are susceptible to grease and other debris which tend to bake onto the stop pins, thereby impeding their adjustment. Further still, the manual adjustment of the gap can lead to operator error, particularly where several knobs have to be adjusted on a single platen.
In another prior system, the gap can be automatically set by adjusting a cam coupled to the platen support arm. However, the cam and mechanical linkages are exposed to grease and other debris which, again, can impede the adjustment of the gap. Also, the cam is not capable of providing the necessary float to accommodate the variations in thicknesses of patties. Spring-loaded stop pins similar to the pins discussed above are required to provide the necessary float.
Thus, there is a need for a two-sided cooking system that includes an automated gap adjustment mechanism. Further, there is a need for a system that automatically determines the gap size for the item being cooked. Even further still, there is a need for a control system that can automatically set a cooking time in accordance with a determined gap size.